Buoyant system for surface effect machines



United States Patent [72] Inventor Jean Henri Berlin Neuilly-sur-Seine, France [21.] Appl. No. 741,992 [22] Filed July 2, 1968 Division of Ser. No. 502,934, Oct. 23, 1965, Pat. No. 3,478,835, which is a continuation of Ser. No. 165,634, Jan. 11, 1962, Pat. No. 3,263,764. [45] Patented Dec. 22, 1970 [73] Assignee Bertln & Cie

Boite Pastale, Plaisir, France a French company [32] Priority Jan. 17,1961 [33] France [31 No. 849,877

Pat. 1,310,483

[54] BUOYANT SYSTEM FOR SURFACE EFFECT Primary Examiner-A. Harry Levy AtmrneyStevens, Davis, Miller and Mosher MACHINES ABSTRACT: A seafaring arr cushion vehicle comprising zcmmsannwing Figs buoyant air-tanks projecting from the undersurface of the [52] U.S.Cl. 180/117, vehicle within the confines of cushion bounding skirts gim- 180/121, 180/127 balled to said air-tanks.

. 4 BUOYANT FOR SURFACE EFFECT MACHINES This is a divisional application of my copending application Ser. No. 502,934 filed Oct. 23, 1965, now Pat. 'No. 3,478,835, which is itself a continuation-inpart of my application Ser. No. 165,634 filed Jan. 11,1962, now Pat. No. 3,263,764.

' The present invention relates to fluid-cushion systems designed to sustain a movable body, for example a vehicle, at a small hover-height above a bearing surface such as the sea.

One of the objects of the present invention is to provide such fluid-cushion systems with buoyancy means for keeping the body afloat when at rest or in case of failure of fluidcushion lift. v

Another object of this invention is to impart buoyancy to said body by means of a buoyant tank fitted thereto so as to be exposed to cushionfluid and partly bound the cushion space.

ln a preferred embodiment of the present invention, the fluid-cushion systems comprise a gimballed wallelement which laterally bounds the fluid-cushion and which is gimballed to said buoyant tank.

Other objects and advantages of the present invention will appear in the following description with reference to the accompanying drawings in which:

. FIG. 1 is a diagrammatic elevation view, partly in section, of a surface effect machine;

FIG. 2 is a corresponding front elevation view; 1

FIG. 3 is a fragmentary perspective view showing contro linkages for the orientation of the fluid-cushion systems.

Referring to FIGS. 1 and 2, there isshown thereon a'platform 1 or rigidsupport frame lifted to a distance D above a bearing surface6 by a plurality of gaseous cushions each supplied by three ejectors 3, theinductive nozzles 4 of which branch off the discharge duct of a compressed gas generator 5, for instance a gas-turbine engine. 1

Each of said gaseous cushions is of the plenum chamber type and confined within a skirt 2 made of supple material and mounted on a supporting frame 7 gimballed by means of two horizontally opposed pivots 8 to a further gimbal 9 which is supported by two horizontally opposed pivots 10 solid with the platform 1 and set at right angles to the axis of the pivots 8. The pivots 10 are fixed to the walls of a flotation tank 21 extending inside each cushion from under the platform 1 to a bottom end 21 'a located at a hover-height l-l above bearing surface 6. v

The upper portion of each skirt '2 provides an oscillation joint, an example being bellows'joint 11 depending from platform 1 and outwardly spaced from the buoyant tank 21, whereby the skirt is ableto move freely in all directions and full tightness with minimum friction is ensured;

Through actuating means such as a joystick or control lever 12, pivotal motion of the skirts is controlled about the two perpendicular axes containing respectively the pivots 8 and the pivots 10. Thus it is possible to simultaneously orientate all the skirts in the same direction, thereby creating a horizontal force in that direction. Alternatively, the skirts could be orientated differentially in order to produce a steering couple.

The platform is further equipped with a front orientable wheel 13 and a rear wheel 14 driven by an engine 17, for providing positive (friction) guidance and propulsion in a manner well known in the motorcycle art. The wheels are linked to the platform 1 by arms 15, 16 provided with suspension elements 18 and 19 designed to support only 10 to 20 percent of the total weight of the vehicle, the major part of the weight being'supported by the gaseous cushions. The suspension elements may be adapted. to permit stiffness adjustment,

as shown for instance in Brueder 2,757,376. V

Valves 20 enable the compressed gas supplied by the gas generating engine to be distributed as desired to the various cushions.

After the engine 5 has been started up, the platform 1 rises on its air cushions and may be piloted by movement of the control lever 12 which orientates the skirts 2. Accelerations obtained thereby, however, must be kept to'a low value in order to avoid diminishing the lifting efficiency, and such acceleration will therefore be suited to translational motion and to low speed'maneuvering.

As a part of the weight of the vehicle is supported by the wheels 13, 14, the propulsion of said vehicle may be effected by means of the rear wheel and the accelerations and decelerations exceed those attained by aerodynamic means, with yet a good propulsive efiiciency. The tandem wheels will in fact ensure good stability when travelling on the ground, even at, cruising speeds, if they support 10 to percent of the weight and if the front wheel 13 is steerable as said hereinbefore. The wheels may be fitted with tires having threads adapted to ensure good traction with the ground.

The effects of the sideway forces due to the wind are thus reduced, and the corresponding tipping couple may be further counterbalanced by suitably operating the valves 20 in a dif ferential manner.

Referring now to FIG. 3, it will be'seen that motion of the platform in the direction of arrows 10l or 102 is determined by swinging a control lever 103 in the direction of arrows 104 or 105. This lever 103 actuates through a 'rod 106 a crank lever 107 fast with a rod 108 journaled in bearings 109, 110, 111. The rod 108 carries two crank levers 112, 113 operating each a rod 1 14 secured to the front of skirt support rings 115, 116. These rings are associated, at the rear, with transmission rods 117v which, through rockers 118 arid rods 119, actuate in their turn support rings 120, 121 of the next following skirts, and so on by means of a succession in cascade of control linkages comprising transmission rods 117,..., rockers 1l8',... and rods 119',...

.It is thus possible to obtain a simultaneous and general inclination of the skirts, thereby generating by reaction a horizontal component force which propels the platform either forwardly in the direction of arrow 101 if the control lever 103 is pushed along arrow 104, or rearwardly in the directionof arrow 102 if the control lever 103 is pulled along arrow 105.

Sideways displacement of the platform along arrows 147 or 148 is determined by actuating the control lever 103 in the direction of arrows 149 or 150. This operation modifies the position of a crosspiece 126 journaled at 127 on a crank lever 151 fast with a rod 152 transmitting movements from lever 103. Such a displacement of the axis of the crosspiece 126 causes a like displacement in translation of the latter and a corresponding displacement in the same direction, to the left or to the right, of horizontal rods 132 and 140 linked respectively to the lower and upper arms 128 and 129 of the cross 126. Through linkages to be described hereafien-the skirts are oriented too in a same lateral direction and a corresponding horizontal component force is created.

In addition to the above translational movements of the platform in the longitudinal direction (arrows 101 and 102) and in the transverse direction (arrows 147 and 148), the platform may also be imparted with a yaw movement or rotation about a vertical axis for steering purposes.

For this purpose, the platforrnis equipped with a swingbar 122 operable by the operators feet and controlling, by means of cables 123 and pulleys 124 and 125, the crosspiece 126 to give to the branches 128, 129 of the latter opposite displacements. In order to obtain a differential orientation of a front group of say four skirts 130 and a rear group of also four skirts 131 (in the case of an 8-skirt vehicle), the skirts of each group are connected with respective branches 128, 129 of the crosspiece 126. Thus, to branch 128 are linked rods 132 and crank levers 133 fast with sleeves 134 to-which are secured crank levers 135 which actuate linkages 136. It is to be noted that these latter linkages do not effect the group of skirts 130 as they are freely mounted on axles 137; they actuate the group of skirts 131 by means of crank levers and rods (not shown on the drawing but similar to crank levers 145 and rods 146 described hereafter).

Control of the group of skirts 130 is effected by means of rods 140 connected to branch 129 of crosspiece 126. These rods 140 actuate linkages 141 through sleeves 142 fast with crank levers 143, 144 and eventually crank levers 145 and rods 146 which control the skirts 130.

It will now be easily seen that, if, instead of imparting op-- posite displacements to rods 132 and 140 by rotating the cross 126 upon actuation of the swingbar 122, the rods 132 and 140 are displaced in the same direction by bodily translating the cross 126 to the left or to the right upon actuation of the control lever 103 along arrows 149 or 150, all the skirts 130 and 131 of both groups will be oriented in the same lateral direction 147 or 148 and this will result in a horizontal thrust component in the opposite direction 148 or 147, as specified above.

An improvement which is applicable to platforms with multiple skirts consists in imparting different elasticity characteristics to the elemental skirts supporting such platforms. As will be readily understood, the geometrical size of each skirt, namely its height and diameter, and its volume in particular, together with its stiffness and the dimensions of its associated supply duct, all affect the instantaneous rate of leakage and determine a natural period of vertical oscillations of the corresponding air cushion. If all the skirts were identical, such vertical oscillations might give rise to resonance phenomena which may detrimentally afiect overall platform sustention. On the other hand, if the elemental skirts be given different sizes, then the natural oscillation periods of the various air cushions will be different and the sustention will tend to be aperiodic.

Thus, in vehicles of this type, the lift and guidance functions may be fulfilled, either independently or jointly, by several difa and it will be well understood by those skilled in the art that various further changes and modifications may be made in the presently preferred embodiments of the ground effect platform hereinbefore disclosed, within the spirit and scope of the invention as set forth in the appended claims."

lclaim: i

1. A surface effect machine comprising a rigid support frame movable at a distance (D) above a bearing surface with the interposition of a pressure fluid cushion formed thereagainst, and a flexible skirt depending from said support frame and extending adjacent said bearing surface for laterally confining said pressure fluid cushion, wherein the improvement comprises a buoyant tank projecting downwardly from said support frame to a bottom end located above said bearing surface at a hover-height (H) smaller than said distance (D), said buoyant tank being surrounded in spaced relationship by a top end section of said skirt.

2, Surface effect machine as claimed in claim 1, further comprising gimbal means fitted to said buoyant tank and-to said skirt, and control means for orienting said gimbal means. 

